Separation of thymus-derived and marrow-derived rat lymphocytes on glass bead columns

Abstract

Rat thoracic duct lymphocytes were passed through columns of fine siliconed glass beads according to the method of Shortman (1966). On the basis of the degree of labelling with uridine in vitro and of surface antigenic markers it was shown that marrow-derived small lymphocytes were preferentially retained on the columns, causing the concentration of thymus-derived small lymphocytes in the filtered cells. Filtered cells retained normal graft-versus-host (GVH) activity. The proportion of thymus-derived small lymphocytes in normal rat lymph was estimated at a maximum of 63–87 per cent. Previous reports on the immunocompetence of filtered cells may readily be explained by these findings.